Commit Graph

605 Commits

Author SHA1 Message Date
Kevin Wolf
d34682cd4a block: Move initialisation of BlockLimits to bdrv_refresh_limits()
This function separates filling the BlockLimits from bdrv_open(), which
allows it to call it from other operations which may change the limits
(e.g. modifications to the backing file chain or bdrv_reopen)

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
2014-01-24 17:40:01 +01:00
Max Reitz
72daa72eee block: Allow reference for bdrv_file_open()
Allow specifying a reference to an existing block device (by name) for
bdrv_file_open() instead of a filename and/or options.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-01-22 12:07:17 +01:00
Peter Crosthwaite
87ea75d5e1 qemu-option: Remove qemu_opts_create_nofail
This is a boiler-plate _nofail variant of qemu_opts_create. Remove and
use error_abort in call sites.

null/0 arguments needs to be added for the id and fail_if_exists fields
in affected callsites due to argument inconsistency between the normal and
no_fail variants.

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-01-06 15:02:30 -05:00
Kevin Wolf
f8413b3c23 qcow2: Zero-initialise first cluster for new images
Strictly speaking, this is only required for has_zero_init() == false,
but it's easy enough to just do a cluster-aligned write that is padded
with zeros after the header.

This fixes that after 'qemu-img create' header extensions are attempted
to be parsed that are really just random leftover data.

Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-12-04 11:29:37 +01:00
Paolo Bonzini
cffb1ec600 block drivers: expose requirement for write same alignment from formats
This will let misaligned but large requests use zero clusters.  This
is important because the cluster size is not guest visible.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-12-03 15:26:49 +01:00
Paolo Bonzini
95de6d7078 block drivers: add discard/write_zeroes properties to bdrv_get_info implementation
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-12-03 15:26:49 +01:00
Kevin Wolf
c9fbb99d41 block: Use BDRV_O_NO_BACKING where appropriate
If you open an image temporarily just because you want to check its size
or get it flushed, there's no real reason to open the whole backing file
chain.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
2013-11-29 17:41:09 +01:00
Peter Lieven
aa7bfbfff7 block: add flags to bdrv_*_write_zeroes
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-11-28 10:30:51 +01:00
Max Reitz
ba2ab2f2ca qcow2: Flush image after creation
Opening the qcow2 image with BDRV_O_NO_FLUSH prevents any flushes during
the image creation. This means that the image has not yet been flushed
to disk when qemu-img create exits. This flush is delayed until the next
operation on the image involving opening it without BDRV_O_NO_FLUSH and
closing (or directly flushing) it. For large images and/or images with a
small cluster size and preallocated metadata, this flush may take a
significant amount of time and may occur unexpectedly.

Reopening the image without BDRV_O_NO_FLUSH right before the end of
qcow2_create2() results in hoisting the potentially costly flush into
the image creation, which is expected to take some time (whereas
successive image operations may be not).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-10-28 17:34:32 +01:00
Max Reitz
6e13610aa4 qcow2: Unset zero_beyond_eof in save_vmstate
Saving the VM state is done using bdrv_pwrite. This function may perform
a read-modify-write, which in this case results in data being read from
beyond the end of the virtual disk. Since we are actually trying to
access an area which is not a part of the virtual disk, zero_beyond_eof
has to be set to false before performing the partial write, otherwise
the VM state may become corrupted.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-10-24 11:50:51 +02:00
Max Reitz
eedff66f21 qcow2: Restore total_sectors value in save_vmstate
Since df2a6f29a5, bdrv_co_do_writev increases the total_sectors value of
a growable block devices on writes after the current end. This leads to
the virtual disk apparently growing in qcow2_save_vmstate, which in turn
affects the disk size captured by the internal snapshot taken directly
afterwards through e.g. the HMP savevm command. Such a "grown" snapshot
cannot be loaded after reopening the qcow2 image, since its disk size
differs from the actual virtual disk size (writing a VM state does not
actually increase the virtual disk size).

Fix this by restoring total_sectors at the end of qcow2_save_vmstate.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-10-24 11:45:06 +02:00
Max Reitz
1fa5cc839a qcow2: Evaluate overlap check options
Evaluate the runtime overlap check options and set
BDRVQcowState.overlap_check appropriately.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-10-11 16:50:00 +02:00
Max Reitz
4092e99d93 qcow2: Array assigning options to OL check bits
Add an array which assigns the option string to its corresponding
overlap check bit.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-10-11 16:50:00 +02:00
Max Reitz
05de7e86ca qcow2: Add overlap-check options
Add runtime options to tune the overlap checks to be performed before
write accesses.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-10-11 16:50:00 +02:00
Max Reitz
3e3553905c qcow2: Make overlap check mask variable
Replace the QCOW2_OL_DEFAULT macro by a variable overlap_check in
BDRVQcowState.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-10-11 16:50:00 +02:00
Max Reitz
231bb26764 qcow2: Use negated overflow check mask
In qcow2_check_metadata_overlap and qcow2_pre_write_overlap_check,
change the parameter signifying the checks to perform from its current
positive form to a negative one, i.e., it will no longer explicitly
specify every check to perform but rather a mask of checks not to
perform.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-10-11 16:50:00 +02:00
Max Reitz
f9bff97143 qcow2: Remove wrong metadata overlap check
In qcow2_write_compressed, if the compression fails, a normal cluster is
written to disk. This is done through bdrv_write on the qcow2 BDS
itself (using the guest offset), thus it is wrong to do a metadata
overlap check before.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-10-11 16:49:59 +02:00
Max Reitz
9e3f08923a qcow2: Add missing space in error message
The error message in qcow2_downgrade about an unsupported refcount
order is missing a space. This patch adds it.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-10-11 16:49:59 +02:00
Max Reitz
37764dfb71 qcow2: Add support for ImageInfoSpecific
Add a new ImageInfoSpecificQCow2 type as a subtype of ImageInfoSpecific.
This contains the compatibility level as a string and an optional
lazy_refcounts boolean (optional means mandatory for compat >= 1.1 and
not available for compat == 0.10).

Also, add qcow2_get_specific_info, which returns this information.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-10-11 14:03:57 +02:00
Jeff Cody
c4217f645d block: qcow2 - used QEMU_PACKED for on-disk structures
QCowHeader and QCowExtension are structs that reside in the on-disk
image format, and are read and written directly via bdrv_pread()/write(),
and as such should be packed to avoid any unintentional struct padding.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-25 20:51:13 +02:00
Max Reitz
3ef6c40ad0 qcow2: Use Error parameter
Employ usage of the new Error ** parameter in qcow2_open, qcow2_create
and associated functions.

Signed-off-by: Max Reitz <mreitz@redhat.com>
2013-09-12 10:12:48 +02:00
Max Reitz
cc84d90ff5 block: Error parameter for create functions
Add an Error ** parameter to bdrv_create and its associated functions to
allow more specific error messages.

Signed-off-by: Max Reitz <mreitz@redhat.com>
2013-09-12 10:12:48 +02:00
Max Reitz
34b5d2c68e block: Error parameter for open functions
Add an Error ** parameter to bdrv_open, bdrv_file_open and associated
functions to allow more specific error messages.

Signed-off-by: Max Reitz <mreitz@redhat.com>
2013-09-12 10:12:48 +02:00
Max Reitz
d5124c00d8 bdrv: Use "Error" for creating images
Add an Error ** parameter to BlockDriver.bdrv_create to allow more
specific error messages.

Signed-off-by: Max Reitz <mreitz@redhat.com>
2013-09-12 10:12:48 +02:00
Max Reitz
015a1036a7 bdrv: Use "Error" for opening images
Add an Error ** parameter to BlockDriver.bdrv_open and
BlockDriver.bdrv_file_open to allow more specific error messages.

Signed-off-by: Max Reitz <mreitz@redhat.com>
2013-09-12 10:12:47 +02:00
Max Reitz
9296b3ed70 qcow2: Implement bdrv_amend_options
Implement bdrv_amend_options for compat, size, backing_file, backing_fmt
and lazy_refcounts.

Downgrading images from compat=1.1 to compat=0.10 is achieved through
handling all incompatible flags accordingly, clearing all compatible and
autoclear flags and expanding all zero clusters.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-12 10:12:46 +02:00
Max Reitz
b6481f376b qcow2: Save refcount order in BDRVQcowState
Save the image refcount order in BDRVQcowState. This will be relevant
for future code supporting different refcount orders than four and also
for code that needs to verify a certain refcount order for an opened
image.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-12 10:12:46 +02:00
Kevin Wolf
1ebf561c11 qcow2: Discard VM state in active L1 after creating snapshot
During savevm, the VM state is written to the active L1 of the image and
then a snapshot is taken. After that, the VM state isn't needed any more
in the active L1 and should be discarded. This is implemented by this
patch.

The impact of not discarding the VM state is that a snapshot can never
become smaller than any previous snapshot (because it would be padded
with old VM state), and more importantly that future savevm operations
cause unnecessary COWs (with associated flushes), which makes subsequent
snapshots much slower.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2013-09-12 10:12:46 +02:00
Kevin Wolf
670df5e3b4 qcow2: Pass discard type to qcow2_discard_clusters()
The function will be used internally instead of only being called for
guest discard requests.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2013-09-12 10:12:46 +02:00
Paolo Bonzini
4bc74be997 block: return get_block_status data and flags for formats
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-09-06 15:25:09 +02:00
Paolo Bonzini
b6b8a33354 block: introduce bdrv_get_block_status API
For now, bdrv_get_block_status is just another name for bdrv_is_allocated.
The next patches will add more flags.

This also touches all block drivers with a mostly mechanical rename.  The
sole exception is cow; because it calls cow_co_is_allocated from the read
code, we keep that function and make cow_co_get_block_status a wrapper.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-09-06 15:25:09 +02:00
Paolo Bonzini
d663640c04 block: expect errors from bdrv_co_is_allocated
Some bdrv_is_allocated callers do not expect errors, but the fallback
in qcow2.c might make other callers trip on assertion failures or
infinite loops.

Fix the callers to always look for errors.

Cc: qemu-stable@nongnu.org
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-09-06 15:25:09 +02:00
Fam Zheng
4f6fd3491c block: make bdrv_delete() static
Manage BlockDriverState lifecycle with refcnt, so bdrv_delete() is no
longer public and should be called by bdrv_unref() if refcnt is
decreased to 0.

This is an identical change because effectively, there's no multiple
reference of BDS now: no caller of bdrv_ref() yet, only bdrv_new() sets
bs->refcnt to 1, so all bdrv_unref() now actually delete the BDS.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-09-06 15:25:08 +02:00
Max Reitz
24530f3e06 qcow2_check: Mark image consistent
If no corruptions remain after an image repair (and no errors have been
encountered), clear the corrupt flag in qcow2_check.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-02 10:15:15 +02:00
Max Reitz
cf93980e77 qcow2: Employ metadata overlap checks
The pre-write overlap check function is now called before most of the
qcow2 writes (aborting it on collision or other error).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-08-30 15:48:43 +02:00
Max Reitz
69c9872653 qcow2: Add corrupt bit
This adds an incompatible bit indicating corruption to qcow2. Any image
with this bit set may not be written to unless for repairing (and
subsequently clearing the bit if the repair has been successful).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-08-30 15:48:43 +02:00
Kevin Wolf
9117b47717 qcow2: Change default for new images to compat=1.1
By the time that qemu 1.7 will be released, enough time will have passed
since qemu 1.1, which is the first version to understand version 3
images, that changing the default shouldn't hurt many people any more
and the benefits of using the new format outweigh the pain.

qemu-iotests already runs with compat=1.1 by default.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2013-08-30 15:28:51 +02:00
Asias He
0d51b4debe block: Introduce bs->zero_beyond_eof
In 4146b46c42e0989cb5842e04d88ab6ccb1713a48 (block: Produce zeros when
protocols reading beyond end of file), we break qemu-iotests ./check
-qcow2 022. This happens because qcow2 temporarily sets ->growable = 1
for vmstate accesses (which are stored beyond the end of regular image
data).

We introduce the bs->zero_beyond_eof to allow qcow2_load_vmstate() to
disable ->zero_beyond_eof temporarily in addition to enable ->growable.

[Since the broken patch "block: Produce zeros when protocols reading
beyond end of file" has not been merged yet, I have applied this fix
*first* and will then apply the next patch to keep the tree bisectable.
-- Stefan]

Suggested-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-08-22 14:10:21 +02:00
Kevin Wolf
8ad1898cf1 qcow2: Change default for new images to compat=1.1
By the time that qemu 1.7 will be released, enough time will have passed
since qemu 1.1, which is the first version to understand version 3
images, that changing the default shouldn't hurt many people any more
and the benefits of using the new format outweigh the pain.

qemu-iotests already runs with compat=1.1 by default.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-08-21 14:41:09 +02:00
Kevin Wolf
64aa99d3e0 qcow2: Use dashes instead of underscores in options
This is what QMP wants to use. The options haven't been enabled in any
release yet, so we're still free to change them.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2013-07-26 21:59:56 +02:00
Peter Lieven
3ac216270a block: change default of .has_zero_init to 0
.has_zero_init defaults to 1 for all formats and protocols.

this is a dangerous default since this means that all
new added drivers need to manually overwrite it to 0 if
they do not ensure that a device is zero initialized
after bdrv_create().

if a driver needs to explicitly set this value to
1 its easier to verify the correctness in the review process.

during review of the existing drivers it turned out
that ssh and gluster had a wrong default of 1.
both protocols support host_devices as backend
which are not by default zero initialized. this
wrong assumption will lead to possible corruption
if qemu-img convert is used to write to such a backend.

vpc and vmdk also defaulted to 1 altough they support
fixed respectively flat extends. this has to be addresses
in separate patches. both formats as well as the mentioned
ssh and gluster are turned to the default of 0 with this
patch for safety.

a similar problem with the wrong default existed for
iscsi most likely because the driver developer did
oversee the default value of 1.

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-06-28 13:52:35 +02:00
Kevin Wolf
0b919fae31 qcow2: Batch discards
This optimises the discard operation for freed clusters by batching
discard requests (both snapshot deletion and bdrv_discard end up
updating the refcounts cluster by cluster).

Note that we don't discard asynchronously, but keep s->lock held. This
is to avoid that a freed cluster is reallocated and written to while the
discard is still in flight.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-06-24 10:25:17 +02:00
Kevin Wolf
67af674e47 qcow2: Options to enable discard for freed clusters
Deleted snapshots are discarded in the image file by default, discard
requests take their default from the -drive discard=... option and other
places that free clusters must always be enabled explicitly.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-06-24 10:25:17 +02:00
Kevin Wolf
6cfcb9b8b9 qcow2: Add refcount update reason to all callers
This adds a refcount update reason to all callers of update_refcounts(),
so that a follow-up patch can use this information to decide whether
clusters that reach a refcount of 0 should be discarded in the image
file.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-06-24 10:25:17 +02:00
Kevin Wolf
2cf7cfa1cd qcow2: Catch some L1 table index overflows
This catches the situation that is described in the bug report at
https://bugs.launchpad.net/qemu/+bug/865518 and goes like this:

    $ qemu-img create -f qcow2 huge.qcow2 $((1024*1024))T
    Formatting 'huge.qcow2', fmt=qcow2 size=1152921504606846976 encryption=off cluster_size=65536 lazy_refcounts=off
    $ qemu-io /tmp/huge.qcow2 -c "write $((1024*1024*1024*1024*1024*1024 - 1024)) 512"
    Segmentation fault

With this patch applied the segfault will be avoided, however the case
will still fail, though gracefully:

    $ qemu-img create -f qcow2 /tmp/huge.qcow2 $((1024*1024))T
    Formatting 'huge.qcow2', fmt=qcow2 size=1152921504606846976 encryption=off cluster_size=65536 lazy_refcounts=off
    qemu-img: The image size is too large for file format 'qcow2'

Note that even long before these overflow checks kick in, you get
insanely high memory usage (up to INT_MAX * sizeof(uint64_t) = 16 GB for
the L1 table), so with somewhat smaller image sizes you'll probably see
qemu aborting for a failed g_malloc().

If you need huge image sizes, you should increase the cluster size to
the maximum of 2 MB in order to get higher limits.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-05-14 16:44:33 +02:00
Stefan Hajnoczi
f4d38bef7c qcow2: allow sub-cluster compressed write to last cluster
Compression in qcow2 requires image length to be a multiple of the
cluster size.  Lift this requirement by zero-padding the final cluster
when necessary.  The virtual disk size is still not cluster-aligned, so
the guest cannot access the zero sectors.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-04-22 10:27:58 +02:00
Kevin Wolf
8d3b1a2d0b block: Introduce bdrv_pwritev() for qcow2_save_vmstate
Directly pass the QEMUIOVector on instead of linearising it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-04-15 08:26:18 +02:00
Kevin Wolf
cf8074b382 block: Introduce bdrv_writev_vmstate
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-04-15 08:26:18 +02:00
Aurelien Jarno
753d9b82c5 aes: move aes.h from include/block to include/qemu
Move aes.h from include/block to include/qemu to show it can be reused
by other subsystems.

Cc: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2013-04-13 13:51:57 +02:00
Kevin Wolf
88c6588c51 qcow2: Allow requests with multiple l2metas
Instead of expecting a single l2meta, have a list of them. This allows
to still have a single I/O request for the guest data, even though
multiple l2meta may be needed in order to describe both a COW overwrite
and a new cluster allocation (typical sequential write case).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-03-28 11:52:44 +01:00
Kevin Wolf
9ee6439e27 qcow2: Remove bogus unlock of s->lock
The unlock wakes up the next coroutine, but the currently running
coroutine will lock it again before it yields, so this doesn't make a
lot of sense.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-03-28 11:52:42 +01:00
Kevin Wolf
787e4a8500 block: Add options QDict to bdrv_file_open() prototypes
The new parameter is unused yet.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2013-03-22 17:51:31 +01:00
Kevin Wolf
acdfb480ba qcow2: Fix segfault in qcow2_invalidate_cache
Need to pass an options QDict to qcow2_open() now. This fixes a segfault
on the migration target with qcow2.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-03-19 11:48:36 +01:00
Paolo Bonzini
381b487d54 qcow2: make is_allocated return true for zero clusters
Otherwise, live migration of the top layer will miss zero clusters and
let the backing file show through.  This also matches what is done in qed.

QCOW2_CLUSTER_ZERO clusters are invalid in v2 image files.  Check this
directly in qcow2_get_cluster_offset instead of replicating the test
everywhere.

Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-03-15 16:07:50 +01:00
Kevin Wolf
74c4510a3c qcow2: Allow lazy refcounts to be enabled on the command line
qcow2 images now accept a boolean lazy_refcounts options. Use it like
this:

  -drive file=test.qcow2,lazy_refcounts=on

If the option is specified on the command line, it overrides the default
specified by the qcow2 header flags that were set when creating the
image.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-03-15 16:07:49 +01:00
Kevin Wolf
de9c0cec6c block: Add options QDict to bdrv_open() prototype
It doesn't do anything yet except storing the options QDict in the
BlockDriverState.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-03-15 16:07:49 +01:00
Kevin Wolf
1a86938f04 block: Add options QDict to .bdrv_open()
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-03-15 16:07:49 +01:00
Stefan Weil
15bac0d54f block: Use error code EMEDIUMTYPE for wrong format in some block drivers
This improves error reports for bochs, cow, qcow, qcow2, qed and vmdk
when a file with the wrong format is selected.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-01-25 18:18:35 +01:00
Kevin Wolf
8d2497c355 qcow2: Fix segfault on zero-length write
One of the recent refactoring patches (commit f50f88b9) didn't take care
to initialise l2meta properly, so with zero-length writes, which don't
even enter the write loop, qemu just segfaulted.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-01-15 09:08:55 +01:00
Paolo Bonzini
1de7afc984 misc: move include files to include/qemu/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:32:39 +01:00
Paolo Bonzini
737e150e89 block: move include files to include/block/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:31:31 +01:00
Paolo Bonzini
7b1b5d1913 qapi: move include files to include/qobject/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:31:31 +01:00
Kevin Wolf
4e95314e2b qcow2: Execute run_dependent_requests() without lock
There's no reason for run_dependent_requests() to hold s->lock, and a
later patch will require that in fact the lock is not held.

Also, before this patch, run_dependent_requests() not only does what its
name suggests, but also removes the l2meta from the list of in-flight
requests. When changing this, it becomes an one-liner, so just inline it
completely.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-12-13 15:37:59 +01:00
Kevin Wolf
280d373579 qcow2: Enable dirty flag in qcow2_alloc_cluster_link_l2
This is closer to where the dirty flag is really needed, and it avoids
having checks for special cases related to cluster allocation directly
in the writev loop.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-12-13 15:37:59 +01:00
Kevin Wolf
f50f88b9fe qcow2: Allocate l2meta only for cluster allocations
Even for writes to already allocated clusters, an l2meta is allocated,
though it stays effectively unused. After this patch, only allocating
requests still have one. Each l2meta now describes an in-flight request
that writes to clusters that are not yet hooked up in the L2 table.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-12-13 15:37:59 +01:00
Kevin Wolf
060bee8943 qcow2: Drop l2meta.cluster_offset
There's no real reason to have an l2meta for normal requests that don't
allocate anything. Before we can get rid of it, we must return the host
cluster offset in a different way.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-12-13 15:37:59 +01:00
Kevin Wolf
cf5c1a231e qcow2: Allocate l2meta dynamically
As soon as delayed COW is introduced, the l2meta struct is needed even
after completion of the request, so it can't live on the stack.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-12-13 15:37:59 +01:00
Kevin Wolf
67a7a0ebe5 qcow2: Move BLKDBG_EVENT out of the lock
We want to use these events to suspend requests for testing concurrent
AIO requests. Suspending requests while they are holding the CoMutex is
rather boring for this purpose.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-12-12 12:33:48 +01:00
Jim Meyering
00ea188125 qcow2: mark this file's sole strncpy use as justified
Acked-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Jim Meyering <meyering@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-10-05 07:58:38 -05:00
Jeff Cody
21d82ac95f block: qcow2 image file reopen
These are the stubs for the file reopen drivers for the qcow2 format.

There is currently nothing that needs to be done by the qcow2 driver
in reopen.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-24 15:15:12 +02:00
Stefan Hajnoczi
058f8f16db block: add BLOCK_O_CHECK for qemu-img check
Image formats with a dirty bit, like qed and qcow2, repair dirty image
files upon open with BDRV_O_RDWR.  Performing automatic repair when
qemu-img check runs is not ideal because the bdrv_open() call repairs
the image before the actual bdrv_check() call from qemu-img.c.

Fix this "double repair" since it leads to confusing output from
qemu-img check.  Tell the block driver that this image is being opened
just for bdrv_check().  This skips automatic repair and qemu-img.c can
invoke it manually with bdrv_check().

Update the golden output for qemu-iotests 039 to reflect the new
qemu-img check output.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-08-10 10:25:12 +02:00
Stefan Hajnoczi
acbe59829e qcow2: mark image clean after repair succeeds
The dirty bit is cleared after image repair succeeds in qcow2_open().
Move this into qcow2_check() so that all callers benefit from this
behavior when fix mode is enabled.

This is necessary so qemu-img check can call .bdrv_check() and mark the
image clean.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-08-10 10:25:12 +02:00
Stefan Hajnoczi
bfe8043e92 qcow2: implement lazy refcounts
Lazy refcounts is a performance optimization for qcow2 that postpones
refcount metadata updates and instead marks the image dirty.  In the
case of crash or power failure the image will be left in a dirty state
and repaired next time it is opened.

Reducing metadata I/O is important for cache=writethrough and
cache=directsync because these modes guarantee that data is on disk
after each write (hence we cannot take advantage of caching updates in
RAM).  Refcount metadata is not needed for guest->file block address
translation and therefore does not need to be on-disk at the time of
write completion - this is the motivation behind the lazy refcount
optimization.

The lazy refcount optimization must be enabled at image creation time:

  qemu-img create -f qcow2 -o compat=1.1,lazy_refcounts=on a.qcow2 10G
  qemu-system-x86_64 -drive if=virtio,file=a.qcow2,cache=writethrough

Update qemu-iotests 031 and 036 since the extension header size changes
when we add feature bit table entries.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-08-06 22:39:14 +02:00
Stefan Hajnoczi
c61d0004bc qcow2: introduce dirty bit
This patch adds an incompatible feature bit to mark images that have not
been closed cleanly.  When a dirty image file is opened a consistency
check and repair is performed.

Update qemu-iotests 031 and 036 since the extension header size changes
when we add feature bit table entries.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-08-06 22:39:14 +02:00
Anthony Liguori
23797df3d9 Merge remote-tracking branch 'mjt/mjt-iov2' into staging
* mjt/mjt-iov2:
  rewrite iov_send_recv() and move it to iov.c
  cleanup qemu_co_sendv(), qemu_co_recvv() and friends
  export iov_send_recv() and use it in iov_send() and iov_recv()
  rename qemu_sendv to iov_send, change proto and move declarations to iov.h
  change qemu_iovec_to_buf() to match other to,from_buf functions
  consolidate qemu_iovec_copy() and qemu_iovec_concat() and make them consistent
  allow qemu_iovec_from_buffer() to specify offset from which to start copying
  consolidate qemu_iovec_memset{,_skip}() into single function and use existing iov_memset()
  rewrite iov_* functions
  change iov_* function prototypes to be more appropriate
  virtio-serial-bus: use correct lengths in control_out() message

Conflicts:
	tests/Makefile

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-07-09 12:35:06 -05:00
Stefan Hajnoczi
b35278f754 qcow2: fix #ifdef'd qcow2_check_refcounts() callers
The DEBUG_ALLOC qcow2.h macro enables additional consistency checks
throughout the code.  This makes it easier to spot corruptions that are
introduced during development.  Since consistency check is an expensive
operation the DEBUG_ALLOC macro is used to compile checks out in normal
builds and qcow2_check_refcounts() calls missed the addition of a new
function argument.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-07-09 15:53:01 +02:00
Stefan Hajnoczi
af7b708db2 qcow2: fix autoclear image header update
The autoclear feature bits can be used for qcow2 file format features
that are safe to "drop" by old programs that do not understand the
feature.  Upon opening the image file unknown autoclear feature bits are
cleared and the image file header is rewritten, but this was happening
too early in the code when critical header fields were not yet loaded.

Process autoclear feature bits after all necessary header information
has been loaded.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-06-15 14:03:43 +02:00
Paolo Bonzini
6af4e9ead4 qcow2: always operate caches in writeback mode
Writethrough does not need special-casing anymore in the qcow2 caches.
The block layer adds flushes after every guest-initiated data write,
and these will also flush the qcow2 caches to the OS.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-06-15 14:03:43 +02:00
Kevin Wolf
166acf546f qcow2: Support for fixing refcount inconsistencies
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-06-15 14:03:42 +02:00
Kevin Wolf
4534ff5426 qemu-img check -r for repairing images
The QED block driver already provides the functionality to not only
detect inconsistencies in images, but also fix them. However, this
functionality cannot be manually invoked with qemu-img, but the
check happens only automatically during bdrv_open().

This adds a -r switch to qemu-img check that allows manual invocation
of an image repair.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-06-15 14:03:42 +02:00
Michael Tokarev
d5e6b1619c change qemu_iovec_to_buf() to match other to,from_buf functions
It now allows specifying offset within qiov to start from and
amount of bytes to copy.  Actual implementation is just a call
to iov_to_buf().

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2012-06-11 23:12:11 +04:00
Michael Tokarev
1b093c480a consolidate qemu_iovec_copy() and qemu_iovec_concat() and make them consistent
qemu_iovec_concat() is currently a wrapper for
qemu_iovec_copy(), use the former (with extra
"0" arg) in a few places where it is used.

Change skip argument of qemu_iovec_copy() from
uint64_t to size_t, since size of qiov itself
is size_t, so there's no way to skip larger
sizes.  Rename it to soffset, to make it clear
that the offset is applied to src.

Also change the only usage of uint64_t in
hw/9pfs/virtio-9p.c, in v9fs_init_qiov_from_pdu() -
all callers of it actually uses size_t too,
not uint64_t.

One added restriction: as for all other iovec-related
functions, soffset must point inside src.

Order of argumens is already good:
 qemu_iovec_memset(QEMUIOVector *qiov, size_t offset,
                   int c, size_t bytes)
vs:
 qemu_iovec_concat(QEMUIOVector *dst,
                   QEMUIOVector *src,
                   size_t soffset, size_t sbytes)
(note soffset is after _src_ not dst, since it applies to src;
for memset it applies to qiov).

Note that in many places where this function is used,
the previous call is qemu_iovec_reset(), which means
many callers actually want copy (replacing dst content),
not concat.  So we may want to add a wrapper like
qemu_iovec_copy() with the same arguments but which
calls qemu_iovec_reset() before _concat().

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2012-06-11 23:12:11 +04:00
Michael Tokarev
03396148bc allow qemu_iovec_from_buffer() to specify offset from which to start copying
Similar to
 qemu_iovec_memset(QEMUIOVector *qiov, size_t offset,
                   int c, size_t bytes);
the new prototype is:
 qemu_iovec_from_buf(QEMUIOVector *qiov, size_t offset,
                     const void *buf, size_t bytes);

The processing starts at offset bytes within qiov.

This way, we may copy a bounce buffer directly to
a middle of qiov.

This is exactly the same function as iov_from_buf() from
iov.c, so use the existing implementation and rename it
to qemu_iovec_from_buf() to be shorter and to match the
utility function.

As with utility implementation, we now assert that the
offset is inside actual iovec.  Nothing changed for
current callers, because `offset' parameter is new.

While at it, stop using "bounce-qiov" in block/qcow2.c
and copy decrypted data directly from cluster_data
instead of recreating a temp qiov for doing that.

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2012-06-11 23:12:11 +04:00
Michael Tokarev
3d9b49254f consolidate qemu_iovec_memset{,_skip}() into single function and use existing iov_memset()
This patch combines two functions into one, and replaces
the implementation with already existing iov_memset() from
iov.c.

The new prototype of qemu_iovec_memset():
  size_t qemu_iovec_memset(qiov, size_t offset, int fillc, size_t bytes)
It is different from former qemu_iovec_memset_skip(), and
I want to make other functions to be consistent with it
too: first how much to skip, second what, and 3rd how many
of it.  It also returns actual number of bytes filled in,
which may be less than the requested `bytes' if qiov is
smaller than offset+bytes, in the same way iov_memset()
does.

While at it, use utility function iov_memset() from
iov.h in posix-aio-compat.c, where qiov was used.

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2012-06-11 23:07:44 +04:00
Jim Meyering
b6c147622d qcow2: don't leak buffer for unexpected qcow_version in header
Signed-off-by: Jim Meyering <meyering@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-25 18:12:54 +02:00
Kevin Wolf
c44bfe4637 qcow2: Don't ignore failure to clear autoclear flags
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-14 17:02:19 +02:00
Paolo Bonzini
5f3777945d block: push bdrv_change_backing_file error checking up from drivers
This check applies to all drivers, but QED lacks it.

Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 10:32:11 +02:00
Zhi Yong Wu
15552c4ad3 qcow2: lock on prealloc
preallocate() will be locked. This is required because
qcow2_alloc_cluster_link_l2() assumes that it runs under a lock that it
can drop while COW is being performed.

Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-07 19:33:18 +02:00
Stefan Weil
b9531b6eed block/qcow2: Add missing GCC_FMT_ATTR to function report_unsupported()
Cc: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-02 18:39:39 +02:00
Kevin Wolf
621f058940 qcow2: Zero write support
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20 15:57:30 +02:00
Kevin Wolf
cfcc4c62ff qcow2: Support for feature table header extension
Instead of printing an ugly bitmask, qemu can now print a more helpful
string even for yet unknown features.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20 15:57:29 +02:00
Kevin Wolf
6377af48b0 qcow2: Support reading zero clusters
This adds support for reading zero clusters in version 3 images.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20 15:57:29 +02:00
Kevin Wolf
6744cbab8c qcow2: Version 3 images
This adds the basic infrastructure to qcow2 to handle version 3 images.
It includes code to create v3 images, allow header updates for v3 images
and checks feature bits.

It still misses support for zero clusters, so this is not a fully
compliant implementation of v3 yet.

The default for creating new images stays at v2 for now.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20 15:57:29 +02:00
Kevin Wolf
68d000a390 qcow2: Ignore reserved bits in get_cluster_offset
With this change, reading from a qcow2 image ignores all reserved bits
that are set in an L1 or L2 table entry.

Now get_cluster_offset() assigns *cluster_offset only the offset without
any other flags. The cluster type is not longer encoded in the offset,
but a positive return value in case of success.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20 15:57:27 +02:00
Paolo Bonzini
29cdb2513c block: push recursive flushing up from drivers
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 14:54:39 +02:00
Kevin Wolf
259b217310 qcow2: Add error messages in qcow2_truncate
qemu-img resize has some limitations with qcow2, but the user is only
told that "this image format does not support resize". Quite confusing,
so add some more detailed error_report() calls and change "this image
format" into "this image".

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-03-12 15:14:06 +01:00
Kevin Wolf
3cce16f44d qcow2: Add some tracing
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-03-12 15:14:06 +01:00
Kevin Wolf
64ca6aee4f qcow2: Reject too large header extensions
Image files that make qemu-img info read several gigabytes into the
unknown header extensions list are bad. Just fail opening the image
if an extension claims to be larger than the header extension area.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-02-29 12:48:47 +01:00
Kevin Wolf
fd29b4bbef qcow2: Fix offset in qcow2_read_extensions
The spec says that the length of extensions is padded to 8 bytes, not
the offset. Currently this is the same because the header size is a
multiple of 8, so this is only about compatibility with future changes
to the header size.

While touching it, move the calculation to a common place instead of
duplicating it for each header extension type.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-02-29 12:48:47 +01:00
Kevin Wolf
423477e556 qcow2: Fix build with DEBUG_EXT enabled
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-02-29 12:48:47 +01:00
Kevin Wolf
75bab85ca0 qcow2: Keep unknown header extension when rewriting header
If we want header extensions to work as compatible extensions, we can't
destroy yet unknown header extensions when rewriting the header (e.g.
for changing the backing file). Save all unknown header extensions in a
list of blobs and include them in a new header.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-02-09 16:17:51 +01:00
Kevin Wolf
e24e49e619 qcow2: Update whole header at once
In order to switch the backing file, qcow2 issues multiple write
requests that only changed a part of the image header. Any failure after
the first one would leave the header in an corrupted state. With this
patch, the whole header is written at once, so we can't fail in the
middle.

At the same time, this gives us a reusable functions that updates all
fields of the qcow2 header and not only the backing file.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-02-09 16:17:51 +01:00
Li Zhi Hui
28c1202ba6 block/qcow2.c: call qcow2_free_snapshots in the function of qcow2_close
Signed-off-by: Li Zhi Hui <zhihuili@linux.vnet.ibm.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-15 12:40:08 +01:00
Anthony Liguori
eb5d5beaeb Merge remote-tracking branch 'kwolf/for-anthony' into staging 2011-12-05 09:39:25 -06:00
Stefan Hajnoczi
e8ee5e4c47 coroutine: add qemu_co_queue_restart_all()
It's common to wake up all waiting coroutines.  Introduce the
qemu_co_queue_restart_all() function to do this instead of looping over
qemu_co_queue_next() in every caller.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-05 14:51:38 +01:00
Stefan Hajnoczi
f8a2e5e3ca block: convert qcow2, qcow2, and vmdk to .bdrv_co_is_allocated()
The qcow2, qcow, and vmdk block drivers are based on coroutines.  They have a
coroutine mutex which protects internal state.  We can convert the
.bdrv_is_allocated() function to .bdrv_co_is_allocated() by holding the mutex
around the cluster lookup operation.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-05 14:51:37 +01:00
Kevin Wolf
42deb29fed qcow2: Return real error code in qcow2_read_snapshots
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-12-05 14:51:35 +01:00
Dong Xu Wang
a968168c58 block: Add coroutine_fn marker to coroutine functions
Looks better when reviewing these source files.

Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-05 14:51:35 +01:00
Dong Xu Wang
9b2260cbd5 fix spelling in block sub directory
Cc: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-12-02 10:50:57 +00:00
Anthony Liguori
06d9260ffa qcow2: implement bdrv_invalidate_cache (v2)
We don't reopen the actual file, but instead invoke the close and open routines.
We specifically ignore the backing file since it's contents are read-only and
therefore immutable.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-11-21 14:58:48 -06:00
Kevin Wolf
eb489bb1ec block: Introduce bdrv_co_flush_to_os
qcow2 has a writeback metadata cache, so flushing a qcow2 image actually
consists of writing back that cache to the protocol and only then flushes the
protocol in order to get everything stable on disk.

This introduces a separate bdrv_co_flush_to_os to reflect the split.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-11 14:02:59 +01:00
Kevin Wolf
c68b89acd6 block: Rename bdrv_co_flush to bdrv_co_flush_to_disk
There are two different types of flush that you can do: Flushing one level up
to the OS (i.e. writing data to the host page cache) or flushing it all the way
down to the disk. The existing functions flush to the disk, reflect this in the
function name.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-11 14:02:59 +01:00
Dong Xu Wang
c95de7e2c4 block: fix qcow2_co_flush deadlock
If qcow2_cache_flush failed, s->lock will not be unlock.

Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-28 19:25:49 +02:00
Paolo Bonzini
6db39ae2e2 block: change discard to co_discard
Since coroutine operation is now mandatory, convert both bdrv_discard
implementations to coroutines.  For qcow2, this means taking the lock
around the operation.  raw-posix remains synchronous.

The bdrv_discard callback is then unused and can be eliminated.

Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-21 17:34:14 +02:00
Paolo Bonzini
8b94ff8573 block: change flush to co_flush
Since coroutine operation is now mandatory, convert all bdrv_flush
implementations to coroutines.  For qcow2, this means taking the lock.
Other implementations are simpler and just forward bdrv_flush to the
underlying protocol, so they can avoid the lock.

The bdrv_flush callback is then unused and can be eliminated.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-21 17:34:14 +02:00
Kevin Wolf
8f1efd00c4 qcow2: Fix bdrv_write_compressed error handling
If during allocation of compressed clusters the cluster was already allocated
uncompressed, fail and properly release the l2_table (the latter avoids a
failed assertion).

While at it, make it return some real error numbers instead of -1.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
2011-10-21 17:34:13 +02:00
Stefan Hajnoczi
6f6dc6565e block: drop redundant bdrv_flush implementation
Block drivers now only need to provide either of .bdrv_co_flush,
.bdrv_aio_flush() or for legacy drivers .bdrv_flush().  Remove
the redundant .bdrv_flush() implementations.

[Paolo Bonzini: change raw driver to bdrv_co_flush]

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-21 17:34:13 +02:00
Frediano Ziglio
dea43a65d6 qcow2: align cluster_data to block to improve performance using O_DIRECT
Signed-off-by: Frediano Ziglio <freddy77@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-12 15:17:22 +02:00
Kevin Wolf
0fa9131a44 qcow2: Fix error cases to run depedent requests
Requests depending on a failed request would end up waiting forever. This fixes
the error path to continue dependent requests even when the request has failed.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-06 11:23:51 +02:00
Kevin Wolf
8e217d5384 qcow2: Properly initialise QcowL2Meta
Dependency list pointers filled with random garbage from the stack aren't a
good idea.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-06 11:23:51 +02:00
Frediano Ziglio
ab0997e0af qcow2: remove memory leak
Signed-off-by: Frediano Ziglio <freddy77@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-23 17:41:15 +02:00
Frediano Ziglio
3fc48d0983 qcow2: Removed QCowAIOCB entirely
Signed-off-by: Frediano Ziglio <freddy77@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-23 17:41:14 +02:00
Frediano Ziglio
5ebaa27e9a qcow2: reindent and use while before the big jump
prepare to remove read/write callbacks

Signed-off-by: Frediano Ziglio <freddy77@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-23 17:41:14 +02:00
Frediano Ziglio
e78c69b89c qcow2: remove common from QCowAIOCB
Signed-off-by: Frediano Ziglio <freddy77@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-23 17:41:14 +02:00
Frediano Ziglio
c2bdd9904b qcow2: remove cluster_offset from QCowAIOCB
Signed-off-by: Frediano Ziglio <freddy77@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-23 17:41:14 +02:00
Frediano Ziglio
c227140397 qcow2: remove l2meta from QCowAIOCB
Signed-off-by: Frediano Ziglio <freddy77@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-23 17:41:14 +02:00
Frediano Ziglio
faf575c136 qcow2: removed cur_nr_sectors field in QCowAIOCB
Signed-off-by: Frediano Ziglio <freddy77@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-23 17:41:14 +02:00
Frediano Ziglio
4617310c33 qcow2: Removed unused AIOCB fields
Signed-off-by: Frediano Ziglio <freddy77@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-23 17:41:14 +02:00
Frediano Ziglio
f5cd8173e7 qcow/qcow2: Allocate QCowAIOCB structure using stack
instead of calling qemi_aio_get use stack

Signed-off-by: Frediano Ziglio <freddy77@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-23 17:41:14 +02:00
Philipp Hahn
6cbc3031c8 qcow2: Fix DEBUG_* compilation
By introducing BlockDriverState compiling qcow2 with DEBUG_ALLOC and DEBUG_EXT
defined got broken.
Define a BdrvCheckResult structure locally which is now needed as the second
argument.

Also fix qcow2_read_extensions() needing BDRVQcowState.

Signed-off-by: Philipp Hahn <hahn@univention.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-23 14:15:17 +02:00
Anthony Liguori
7267c0947d Use glib memory allocation and free functions
qemu_malloc/qemu_free no longer exist after this commit.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-08-20 23:01:08 -05:00
Kevin Wolf
68d100e905 qcow2: Use coroutines
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-02 15:53:41 +02:00
Markus Armbruster
6daf194dde Strip trailing '\n' from error_report()'s first argument
error_report() prepends location, and appends a newline.  The message
constructed from the arguments should not contain a newline.  Fix the
obvious offenders.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-06-24 09:13:36 +01:00
Kevin Wolf
42496d6240 qcow2: Avoid direct AIO callback
bdrv_aio_* must not call the callback before returning to its caller. In qcow2,
this could happen in some error cases. This starts the real requests processing
in a BH to avoid this situation.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-06-14 17:03:25 +02:00
Kevin Wolf
99cce9fa4e qemu-img create: Fix displayed default cluster size
When not specifying a cluster size on the command line, qemu-img printed
a cluster size of 0:

    Formatting '/tmp/test.qcow2', fmt=qcow2 size=67108864
    encryption=off cluster_size=0

This patch adds the default cluster size to the QEMUOptionParameter list, so
that it displays the default value that is used.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-06-08 11:56:40 +02:00
Christoph Hellwig
a659979328 block: clarify the meaning of BDRV_O_NOCACHE
Change BDRV_O_NOCACHE to only imply bypassing the host OS file cache,
but no writeback semantics.  All existing callers are changed to also
specify BDRV_O_CACHE_WB to give them writeback semantics.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-06-08 10:39:32 +02:00
Kevin Wolf
e8cdcec123 qcow2: Report error for version > 2
The qcow2 driver is now declared responsible for any QCOW image that has
version 2 or greater (before this, version 3 would be detected as raw).

For everything newer than version 2, an error is reported.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
2011-02-10 13:23:56 +01:00
Kevin Wolf
8af3648843 qcow2: Fix error handling for reading compressed clusters
When reading a compressed cluster failed, qcow2 falsely returned success.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
2011-02-10 13:23:44 +01:00
Kevin Wolf
3ab4c7e92d qcow2: Fix error handling for immediate backing file read failure
Requests could return success even though they failed when bdrv_aio_readv
returned NULL for a backing file read.

Reported-by: Chunqiang Tang <ctang@us.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-02-10 13:23:44 +01:00
Chunqiang Tang
e0d9c6f937 QCOW2: bug fix - read base image beyond its size
This patch fixes the following bug in QCOW2. For a QCOW2 image that is larger
than its base image, when handling a read request straddling over the end of the
base image, the QCOW2 driver attempts to read beyond the end of the base image
and the request would fail.

This bug was found by Fast Virtual Disk (FVD)'s fully automated testing tool.
The following test triggered the bug.

dd if=/dev/zero of=/var/ramdisk/truth.raw count=0 bs=1 seek=1098561536
dd if=/dev/zero of=/var/ramdisk/zero-500M.raw count=0 bs=1 seek=593099264
./qemu-img create -f qcow2 -ocluster_size=65536,backing_fmt=blksim -b /var/ramdisk/zero-500M.raw /var/ramdisk/test.qcow2 1098561536
./qemu-io --auto --seed=30477694 --truth=/var/ramdisk/truth.raw --format=qcow2 --test=blksim:/var/ramdisk/test.qcow2 --verify_write=true --compare_before=false --compare_after=true --round=100000 --parallel=100 --io_size=10485760 --fail_prob=0 --cancel_prob=0 --instant_qemubh=true

Signed-off-by: Chunqiang Tang <ctang@us.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-02-10 13:23:44 +01:00
Kevin Wolf
e1a7107f2d qcow2: Really use cache=unsafe for image creation
For cache=unsafe we also need to set BDRV_O_CACHE_WB, otherwise we have some
strange unsafe writethrough mode.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-02-07 09:44:22 +01:00
Kevin Wolf
5ea929e3d1 qcow2: Add bdrv_discard support
This adds a bdrv_discard function to qcow2 that frees the discarded clusters.
It does not yet pass the discard on to the underlying file system driver, but
the space can be reused by future writes to the image.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-01-31 10:03:00 +01:00
Kevin Wolf
29c1a7301a qcow2: Use QcowCache
Use the new functions of qcow2-cache.c for everything that works on refcount
block and L2 tables.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-01-24 16:41:49 +01:00
Jes Sorensen
6d85a57e20 Add proper -errno error return values to qcow2_open()
In addition this adds missing braces to the function to be consistent
with the coding style.

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-12-17 16:15:04 +01:00
Jes Sorensen
7c80ab3f21 block/qcow2.c: rename qcow_ functions to qcow2_
It doesn't really make sense for functions in qcow2.c to be named
qcow_ so convert the names to match correctly.

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-12-17 16:15:01 +01:00
Kevin Wolf
205ef7961f block: Allow bdrv_flush to return errors
This changes bdrv_flush to return 0 on success and -errno in case of failure.
It's a requirement for implementing proper error handle in users of bdrv_flush.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2010-11-04 12:52:16 +01:00
edison
51ef67270b Copy snapshots out of QCOW2 disk
In order to backup snapshots, created from QCOW2 iamge, we want to copy snapshots out of QCOW2 disk to a seperate storage.
The following patch adds a new option in "qemu-img": qemu-img convert -f qcow2 -O qcow2 -s snapshot_name src_img bck_img.
Right now, it only supports to copy the full snapshot, delta snapshot is on the way.

Changes from V1: all the comments from Kevin are addressed:
Add read-only checking
Fix coding style
Change the name from bdrv_snapshot_load to bdrv_snapshot_load_tmp

Signed-off-by: Disheng Su <edison@cloud.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-10-22 14:49:35 +02:00
Kevin Wolf
9b036055ef qcow2: Remove old image creation function
They have been #ifdef'd out by the previous patch.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-10-22 14:49:35 +02:00
Kevin Wolf
a9420734b6 qcow2: Simplify image creation
Instead of doing lots of magic for setting up initial refcount blocks and stuff
create a minimal (inconsistent) image, open it and initialize the rest with
regular qcow2 functions.

This is a complete rewrite of the image creation function. The old
implementating is #ifdef'd out and will be removed by the next patch (removing
it here would have made the diff unreadable because diff tries to find
similarities when it's really a rewrite)

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-10-22 14:49:35 +02:00
Stefan Hajnoczi
72893756e0 qcow2: Support exact L1 table growth
The L1 table grow operation includes a size calculation that bumps up
the new L1 table size in order to anticipate the size needs of vmstate
data.  This helps reduce the number of times that the L1 table has to be
grown when vmstate data is appended.

This size overhead is not necessary during image creation,
bdrv_truncate(), or snapshot goto operations.  In fact, existing
qemu-iotests that exercise table growth are no longer able to trigger it
because image creation preallocates an L1 table that is too large after
changes to qcow_create2().

This patch keeps the size calculation but also adds exact growth for
callers that do not want to inflate the L1 table size unnecessarily.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-10-22 14:49:35 +02:00
Kevin Wolf
6f5f060b73 qcow2: Avoid bounce buffers for AIO write requests
qcow2 used to use bounce buffers for any AIO requests. This does not only imply
unnecessary copying, but also unbounded allocations which should be avoided.

This patch removes bounce buffers from the normal AIO write path. Encrypted
images continue to use a bounce buffer, however with constant size.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-09-21 15:39:43 +02:00
Kevin Wolf
bd28f83565 qcow2: Avoid bounce buffers for AIO read requests
qcow2 used to use bounce buffers for any AIO requests. This does not only imply
unnecessary copying, but also unbounded allocations which should be avoided.

This patch removes bounce buffers from the normal AIO read path, and constrains
them to a constant size for encrypted images.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-09-21 15:39:42 +02:00
Kevin Wolf
9ac228e02c qcow2/vdi: Change check to distinguish error cases
This distinguishes between harmless leaks and real corruption. Hopefully users
better understand what qemu-img check wants to tell them.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-07-06 17:05:49 +02:00
Kevin Wolf
19dbcbf7cc qcow2: Fix error handling during metadata preallocation
People were wondering why qemu-img check failed after they tried to preallocate
a large qcow2 file and ran out of disk space.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-07-02 13:18:01 +02:00
Kevin Wolf
8b3b720620 qcow2: Use bdrv_(p)write_sync for metadata writes
Use bdrv_(p)write_sync to ensure metadata integrity in case of a crash.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-06-22 14:38:02 +02:00
Kevin Wolf
1c46efaa0a qcow2: Allow qcow2_get_cluster_offset to return errors
qcow2_get_cluster_offset() looks up a given virtual disk offset and returns the
offset of the corresponding cluster in the image file. Errors (e.g. L2 table
can't be read) are currenctly indicated by a return value of 0, which is
unfortuately the same as for any unallocated cluster. So in effect we can't
check for errors.

This makes the old return value a by-reference parameter and returns the usual
0/-errno error code.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-05-28 13:29:11 +02:00
Blue Swirl
0bfcd599e3 Fix %lld or %llx printf format use
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2010-05-22 08:02:12 +00:00
Kevin Wolf
b666d23950 block: Avoid unchecked casts for AIOCBs
Use container_of for one direction and &acb->common for the other one.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-05-17 10:20:05 +02:00
Kevin Wolf
92b30744d7 qcow2: Remove static forward declaration
OpenBSDs gcc is said to generate warnings for this declaration, so don't
reference bdrv_qcow2 directly, but look it up using bdrv_find_format.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2010-05-07 17:11:37 +00:00
Kevin Wolf
de5f3f40af Revert "Fix OpenBSD build"
This reverts commit 20d97356c9.
The BlockDriver definition should stay at the end of source files.

Conflicts:

	block/qcow2.c

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2010-05-07 17:11:02 +00:00
Stefan Hajnoczi
419b19d9b4 qcow2: Implement bdrv_truncate() for growing images
This patch adds the ability to grow qcow2 images in-place using
bdrv_truncate().  This enables qemu-img resize command support for
qcow2.

Snapshots are not supported and bdrv_truncate() will return -ENOTSUP.
The notion of resizing an image with snapshots could lead to confusion:
users may expect snapshots to remain unchanged, but this is not possible
with the current qcow2 on-disk format where the header.size field is
global instead of per-snapshot.  Others may expect snapshots to change
size along with the current image data.  I think it is safest to not
support snapshots and perhaps add behavior later if there is a
consensus.

Backing images continue to work.  If the image is now larger than its
backing image, zeroes are read when accessing beyond the end of the
backing image.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-05-03 10:07:32 +02:00
Kevin Wolf
66f82ceed6 block: Open the underlying image file in generic code
Format drivers shouldn't need to bother with things like file names, but rather
just get an open BlockDriverState for the underlying protocol. This patch
introduces this behaviour for bdrv_open implementation. For protocols which
need to access the filename to open their file/device/connection/... a new
callback bdrv_file_open is introduced which doesn't get an underlying file
opened.

For now, also some of the more obscure formats use bdrv_file_open because they
open() the file themselves instead of using the block.c functions. They need to
be fixed in later patches.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-05-03 10:07:30 +02:00
Blue Swirl
20d97356c9 Fix OpenBSD build
GCC 3.3.5 generates warnings for static forward declarations of data, so
rearrange code to use static forward declarations of functions instead.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2010-04-23 20:19:47 +00:00
Stefan Hajnoczi
d4c146f0da qcow2: Use QLIST_FOREACH_SAFE macro
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-04-23 16:21:58 +02:00
Kevin Wolf
d6e9098e10 Replace calls of old bdrv_open
What is known today as bdrv_open2 becomes the new bdrv_open. All remaining
callers of the old function are converted to the new one. In some places they
even know the right format, so they should have used bdrv_open2 from the
beginning.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-04-23 16:08:46 +02:00
Kevin Wolf
4768fa902c qcow2: Fix creation of large images
qcow_create2 assumes that the new image will only need one cluster for its
refcount table initially. Obviously that's not true any more when the image is
big enough (exact value depends on the cluster size).

This patch calculates the refcount table size dynamically.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-04-23 16:08:46 +02:00
Kevin Wolf
8252278afb qcow2: Trigger blkdebug events
This adds blkdebug events to qcow2 to allow injecting I/O errors in specific
places.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-04-23 16:08:46 +02:00
Kevin Wolf
c644db3d53 qcow2: Remove request from in-flight list after error
If we complete a request with a failure we need to remove it from the list of
requests that are in flight. If we don't do it, the next time the same AIOCB is
used for a cluster allocation it will create a loop in the list and qemu will
hang in an endless loop.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2010-04-10 01:25:30 +02:00
Kevin Wolf
171e3d6b99 qcow2: Don't ignore immediate read/write failures
Returning -EIO is far from optimal, but at least it's an error code.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2010-04-10 01:23:08 +02:00
Juan Quintela
bef57da55c qcow2: return errno instead of -1
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-03-09 11:23:00 -06:00
Kevin Wolf
6f745bdaac qcow2: Fix image creation regression
When checking for errors, commit db89119d compares with the wrong values,
failing image creation even when there was no error. Additionally, if an
error has occured, we can't preallocate the image (it's likely broken).

This unbreaks test 023 of qemu-iotests.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-02-23 13:23:29 -06:00
Christoph Hellwig
7b88e48ba5 qcow2: rename two QCowAIOCB members
The n member is not very descriptive and very hard to grep, rename it to
cur_nr_sectors to better indicate what it is used for.  Also rename
nb_sectors to remaining_sectors as that is what it is used for.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-26 15:45:00 -06:00
Naphtali Sprei
058fc8c768 Ask for read-write permissions when opening files
Found some places that seems needs this explicitly, now that
read-write is not the default.

Signed-off-by: Naphtali Sprei <nsprei@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-26 15:42:01 -06:00
Kirill A. Shutemov
db89119d40 block/qcow2.c: fix warnings with _FORTIFY_SOURCE
CC    block/qcow2.o
cc1: warnings being treated as errors
block/qcow2.c: In function 'qcow_create2':
block/qcow2.c:829: error: ignoring return value of 'write', declared with attribute warn_unused_result
block/qcow2.c:838: error: ignoring return value of 'write', declared with attribute warn_unused_result
block/qcow2.c:839: error: ignoring return value of 'write', declared with attribute warn_unused_result
block/qcow2.c:841: error: ignoring return value of 'write', declared with attribute warn_unused_result
block/qcow2.c:844: error: ignoring return value of 'write', declared with attribute warn_unused_result
block/qcow2.c:849: error: ignoring return value of 'write', declared with attribute warn_unused_result
block/qcow2.c:852: error: ignoring return value of 'write', declared with attribute warn_unused_result
block/qcow2.c:855: error: ignoring return value of 'write', declared with attribute warn_unused_result
make: *** [block/qcow2.o] Error 1

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-26 14:59:20 -06:00
Kevin Wolf
148da7ea9d qcow2: Return 0/-errno in qcow2_alloc_cluster_offset
Returning 0/-errno allows it to distingush different errors classes. The
cluster offset of newly allocated clusters is now returned in the QCowL2Meta
struct.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-26 14:59:19 -06:00
Kevin Wolf
1d36e3aae3 qcow2: Fix error handling in qcow_save_vmstate
Don't assume success but pass the bdrv_pwrite return value on.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-26 14:59:19 -06:00
Kevin Wolf
f8012c135e qcow/qcow2: implement bdrv_aio_flush
Now that we do not have to flush the backing device anymore implementing
the bdrv_aio_flush method for image formats is trivial.

[hch: forward ported to qemu mainline from a product tree]

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-13 17:14:15 -06:00
Kevin Wolf
756e6736a1 block: Add bdrv_change_backing_file
Introduce the functions needed to change the backing file of an image. The
function is implemented for qcow2.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-13 17:14:15 -06:00
Kevin Wolf
e1c7f0e3f9 qcow2: Store exact backing format length
Currently qcow2 unnecessarily rounds up the length of the backing format string
to the next multiple of 8. At the same time, the array in BlockDriverState can
only hold 15 characters, so in effect backing formats with 9 characters or more
don't work (e.g. host_device).

Save the real string length and things start to work for all valid image format
names.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-12-03 11:45:49 -06:00
Stefan Weil
d191d12d5f qcow2: Allow qcow2 disk images with size zero
Images with disk size 0 may be used for
VM snapshots, but not to save normal block data.

It is possible to create such images using
qemu-img, but opening them later fails.

So even "qemu-img info image.qcow2" is not
possible for an image created with
"qemu-img create -f qcow2 image.qcow2 0".

This is fixed here.

Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-11-09 08:43:01 -06:00
Kevin Wolf
72ecf02d7d Revert "qcow2: Bring synchronous read/write back to life"
It was merely a workaround and the real fix is done now.
This reverts commit ef845c3bf4.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-27 12:28:59 -05:00
Kevin Wolf
ef845c3bf4 qcow2: Bring synchronous read/write back to life
When the synchronous read and write functions were dropped, they were replaced
by generic emulation functions. Unfortunately, these emulation functions don't
provide the same semantics as the original functions did.

The original bdrv_read would mean that we read some data synchronously and that
we won't be interrupted during this read. The latter assumption is no longer
true with the emulation function which needs to use qemu_aio_poll and therefore
allows the callback of any other concurrent AIO request to be run during the
read. Which in turn means that (meta)data read earlier could have changed and
be invalid now. qcow2 is not prepared to work in this way and it's just scary
how many places there are where other requests could run.

I'm not sure yet where exactly it breaks, but you'll see breakage with virtio
on qcow2 with a backing file. Providing synchronous functions again fixes the
problem for me.

Patchworks-ID: 35437
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-15 09:32:04 -05:00
Blue Swirl
72cf2d4f0e Fix sys-queue.h conflict for good
Problem: Our file sys-queue.h is a copy of the BSD file, but there are
some additions and it's not entirely compatible. Because of that, there have
been conflicts with system headers on BSD systems. Some hacks have been
introduced in the commits 15cc923584,
f40d753718,
96555a96d7 and
3990d09adf but the fixes were fragile.

Solution: Avoid the conflict entirely by renaming the functions and the
file. Revert the previous hacks.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2009-09-12 07:36:22 +00:00
Kevin Wolf
f214978a42 qcow2: Order concurrent AIO requests on the same unallocated cluster
When two AIO requests write to the same cluster, and this cluster is
unallocated, currently both requests allocate a new cluster and the second one
merges the first one when it is completed. This means an cluster allocation, a
read and a cluster deallocation which cause some overhead. If we simply let the
second request wait until the first one is done, we improve overall performance
with AIO requests (specifially, qcow2/virtio combinations).

This patch maintains a list of in-flight requests that have allocated new
clusters. A second request touching the same cluster is limited so that it
either doesn't touch the allocation of the first request (so it can have a
non-overlapping allocation) or it waits for the first request to complete.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-09-09 17:31:26 -05:00
Kevin Wolf
ea80b906f4 qcow2: Fix metadata preallocation
The wrong version of the preallocation patch has been applied, so this is the
remaining diff.

We can't use truncate to grow the image file to the right size because we don't
know if metadata has been written after the last data cluster. In this case
truncate would shrink the file and destroy its metadata. Write a zero sector at
the end of the virtual disk instead to ensure that the file is big enough.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-09-09 17:31:26 -05:00
Blue Swirl
2000cbc50d Fix gcc 3 warning about uninitialized variable
If nb_sectors is 0, cluster_offset will not be initialized.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2009-08-29 16:37:26 +03:00
Kevin Wolf
a35e1c177d qcow2: Metadata preallocation
This introduces a qemu-img create option for qcow2 which allows the metadata to
be preallocated, i.e. clusters are reserved in the refcount table and L1/L2
tables, but no data is written to them. Metadata is quite small, so this
happens in almost no time.

Especially with qcow2 on virtio this helps to gain a bit of performance during
the initial writes. However, as soon as create a snapshot, we're back to the
normal slow speed, obviously. So this isn't the real fix, but kind of a cheat
while we're still having trouble with qcow2 on virtio.

Note that the option is disabled by default and needs to be specified
explicitly using qemu-img create -f qcow2 -o preallocation=metadata.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-08-27 20:30:20 -05:00
Christoph Hellwig
45566e9c99 replace bdrv_{get, put}_buffer with bdrv_{load, save}_vmstate
The VM state offset is a concept internal to the image format.  Replace
the old bdrv_{get,put}_buffer method that require an index into the
image file that is constructed from the VM state offset and an offset
into the vmstate with the bdrv_{load,save}_vmstate that just take an
offset into the VM state.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-07-16 08:28:13 -05:00
Kevin Wolf
3f6a3ee51e qcow2: Fix L1 table memory allocation
Contrary to what one could expect, the size of L1 tables is not cluster
aligned. So as we're writing whole sectors now instead of single entries,
we need to ensure that the L1 table in memory is large enough; otherwise
write would access memory after the end of the L1 table.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-07-10 13:44:29 -05:00
Kevin Wolf
0aa217e461 qcow2: Make cache=writethrough default
The performance of qcow2 has improved meanwhile, so we don't need to
special-case it any more. Switch the default to write-through caching
like all other block drivers.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-07-09 16:06:37 -05:00
Filip Navara
14899cdf3a Fix QCOW2 debugging code to compile again
Updated to use C99 comments.

Signed-off-by: Filip Navara <filip.navara@gmail.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-06-29 08:52:40 -05:00
Kevin Wolf
ed6ccf0f51 qcow2: Rename global functions
The qcow2 source is now split into several more manageable files. During the
conversion quite some functions that were static before needed to be changed to
be global to make the source compile again.

We were lucky enough not to get name conflicts with these additional global
names, but they are not nice. This patch adds a qcow2_ prefix to all of the
global functions in qcow2.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-06-16 15:18:36 -05:00
Kevin Wolf
c142442b06 qcow2: Split out snapshot functions
qcow2-snapshot.c contains the code related to snapshotting.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-06-16 15:18:36 -05:00
Kevin Wolf
45aba42fba qcow2: Split out guest cluster functions
qcow2-cluster.c contains all functions related to the management of guest
clusters, i.e. what the guest sees on its virtual disk. This code is about
mapping these guest clusters to host clusters in the image file using the
two-level lookup tables.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-06-16 15:18:36 -05:00
Kevin Wolf
f7d0fe0239 qcow2: Split out refcount handling
qcow2-refcount.c contains all functions which are related to cluster
allocation and management in the image file. A large part of this is the
reference counting of these clusters.

Also a header file qcow2.h is introduced which will contain the interface of
the split qcow2 modules.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-06-16 15:18:36 -05:00
Kevin Wolf
9ccb258e28 qcow2: Change default cluster size to 64k
Larger cluster sizes mean less metadata. This has been discussion a few times,
let's do it now. This turns 64k clusters on by default for new images.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-06-16 15:18:36 -05:00
Kevin Wolf
db08adf526 qemu-img: Print available options with -o ?
This patch adds a small help text to each of the options in the block drivers
which can be displayed by using qemu-img create -f fmt -o ?

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2009-06-06 18:38:57 +03:00
Christoph Hellwig
c16b5a2ca0 fully split aio_pool from BlockDriver
Now that we have a separate aio pool structure we can remove those
aio pool details from BlockDriver.

Every driver supporting AIO now needs to declare a static AIOPool
with the aiocb size and the cancellation method.  This cleans up the
current code considerably and will make it cleaner and more obvious
to support two different aio implementations behind a single
BlockDriver.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-27 09:46:03 -05:00
Kevin Wolf
a980c98cf1 qcow2: Update multiple refcounts at once
Don't write each single changed refcount block entry to the disk after it is
written, but update all entries of the block and write all of them at once.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-27 09:45:20 -05:00
Kevin Wolf
44ff42de1c qcow2: Refactor update_refcount
This is a preparation patch with no functional changes. It moves the allocation
of new refcounts block to a new function and makes update_cluster_refcount (for
one cluster) call update_refcount (for multiple clusters) instead the other way
round.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-27 09:45:15 -05:00
Kevin Wolf
ade406775d qcow/qcow2: Drop synchronous qcow_write()
There is only one (internal) user left and it can be switched to the normal
emulation provided in block.c

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-27 09:45:10 -05:00
Kevin Wolf
73c632edc4 qcow2: Allow different cluster sizes
Add an option to specify the cluster size of a newly created qcow2 image.
Default is 4k which is the same value that was hard-coded before.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-22 10:50:32 -05:00
Kevin Wolf
0e7e1989f7 Convert all block drivers to new bdrv_create
Now we can make use of the newly introduced option structures. Instead of
having bdrv_create carry more and more parameters (which are format specific in
most cases), just pass a option structure as defined by the driver itself.

bdrv_create2() contains an emulation of the old interface to simplify the
transition.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-22 10:50:31 -05:00
malc
eb0b64f7aa Do not attempt to allocate sn_tab when there are no snapshots
This was caught by a7d27b536f which
aborted on this attempt, thanks to Alex Ivanov for report.

Signed-off-by: malc <av1474@comtv.ru>
2009-05-21 05:40:53 +04:00
Anthony Liguori
019d6b8ff0 Move block drivers into their own directory
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-14 16:13:46 -05:00